Commit 187d4c6b authored by Petr Machata's avatar Petr Machata Committed by David S. Miller
Browse files

nexthop: Add netlink handlers for bucket get 



Allow getting (but not setting) individual buckets to inspect the next hop
mapped therein, idle time, and flags.

Signed-off-by: default avatarPetr Machata <petrm@nvidia.com>
Reviewed-by: default avatarIdo Schimmel <idosch@nvidia.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8a1bbabb

net/ipv4/nexthop.c

+109 −1
Original line number Diff line number Diff line
@@ -66,6 +66,15 @@ static const struct nla_policy rtm_nh_res_bucket_policy_dump[] = { 
	[NHA_RES_BUCKET_NH_ID]	= { .type = NLA_U32 },

};



static const struct nla_policy rtm_nh_policy_get_bucket[] = {

	[NHA_ID]		= { .type = NLA_U32 },

	[NHA_RES_BUCKET]	= { .type = NLA_NESTED },

};



static const struct nla_policy rtm_nh_res_bucket_policy_get[] = {

	[NHA_RES_BUCKET_INDEX]	= { .type = NLA_U16 },

};



static bool nexthop_notifiers_is_empty(struct net *net)

{

	return !net->nexthop.notifier_chain.head;
@@ -3381,6 +3390,105 @@ static int rtm_dump_nexthop_bucket(struct sk_buff *skb, 
	return err;

}



static int nh_valid_get_bucket_req_res_bucket(struct nlattr *res,

					      u16 *bucket_index,

					      struct netlink_ext_ack *extack)

{

	struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_get)];

	int err;



	err = nla_parse_nested(tb, ARRAY_SIZE(rtm_nh_res_bucket_policy_get) - 1,

			       res, rtm_nh_res_bucket_policy_get, extack);

	if (err < 0)

		return err;



	if (!tb[NHA_RES_BUCKET_INDEX]) {

		NL_SET_ERR_MSG(extack, "Bucket index is missing");

		return -EINVAL;

	}



	*bucket_index = nla_get_u16(tb[NHA_RES_BUCKET_INDEX]);

	return 0;

}



static int nh_valid_get_bucket_req(const struct nlmsghdr *nlh,

				   u32 *id, u16 *bucket_index,

				   struct netlink_ext_ack *extack)

{

	struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get_bucket)];

	int err;



	err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,

			  ARRAY_SIZE(rtm_nh_policy_get_bucket) - 1,

			  rtm_nh_policy_get_bucket, extack);

	if (err < 0)

		return err;



	err = __nh_valid_get_del_req(nlh, tb, id, extack);

	if (err)

		return err;



	if (!tb[NHA_RES_BUCKET]) {

		NL_SET_ERR_MSG(extack, "Bucket information is missing");

		return -EINVAL;

	}



	err = nh_valid_get_bucket_req_res_bucket(tb[NHA_RES_BUCKET],

						 bucket_index, extack);

	if (err)

		return err;



	return 0;

}



/* rtnl */

static int rtm_get_nexthop_bucket(struct sk_buff *in_skb, struct nlmsghdr *nlh,

				  struct netlink_ext_ack *extack)

{

	struct net *net = sock_net(in_skb->sk);

	struct nh_res_table *res_table;

	struct sk_buff *skb = NULL;

	struct nh_group *nhg;

	struct nexthop *nh;

	u16 bucket_index;

	int err;

	u32 id;



	err = nh_valid_get_bucket_req(nlh, &id, &bucket_index, extack);

	if (err)

		return err;



	nh = nexthop_find_group_resilient(net, id, extack);

	if (IS_ERR(nh))

		return PTR_ERR(nh);



	nhg = rtnl_dereference(nh->nh_grp);

	res_table = rtnl_dereference(nhg->res_table);

	if (bucket_index >= res_table->num_nh_buckets) {

		NL_SET_ERR_MSG(extack, "Bucket index out of bounds");

		return -ENOENT;

	}



	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);

	if (!skb)

		return -ENOBUFS;



	err = nh_fill_res_bucket(skb, nh, &res_table->nh_buckets[bucket_index],

				 bucket_index, RTM_NEWNEXTHOPBUCKET,

				 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,

				 0, extack);

	if (err < 0) {

		WARN_ON(err == -EMSGSIZE);

		goto errout_free;

	}



	return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);



errout_free:

	kfree_skb(skb);

	return err;

}



static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)

{

	unsigned int hash = nh_dev_hashfn(dev->ifindex);
@@ -3604,7 +3712,7 @@ static int __init nexthop_init(void) 
	rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);

	rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);



	rtnl_register(PF_UNSPEC, RTM_GETNEXTHOPBUCKET, NULL,

	rtnl_register(PF_UNSPEC, RTM_GETNEXTHOPBUCKET, rtm_get_nexthop_bucket,

		      rtm_dump_nexthop_bucket, 0);



	return 0;